*Dermiforma.*[142]--This is an American preparation, put on the market by the Nowak Manufacturing Co. of Chicago, and is described as a natural bacterial liquor of organic acidity. For 1200 lb. scudded calf skins, 9 gallons of the liquid Dermiforma are used at 100° F., one-third being put in to start with and the remainder added gradually; time required, about 3 hours. For sheep skin a less quantity is required. This bate was found to be a preparation of whey, and contains a certain quantity (18–20 per cent.) of lactic and other organic acids, produced by fermentation; it is therefore to be classed as a drench, and is not a true bate or puer, since tryptic ferments or bacteria are not present. [142] See Chapter VIII.; also J.S.C.I. 1906, p. 647. *Puerine.*--Another bate, manufactured in America is advertised under the name of Puerine, “the long-looked-for bacterial bate.” The manufacturers give the following directions for use. To start a bating liquor, 10 lb. of the dry powdered puerine is put into a half barrel of warm water (100° F.), and allowed to stand for 3 or 4 days, maintaining the temperature by occasionally warming the infusion with a steam pipe. This amount is sufficient for each 100 galls. water in the bating vat or paddle wheel, and will bate as many skins as can be turned in 100 galls. When the warm infusion of puerine has stood the required length of time, in order to generate the necessary bacterial ferments, the bating vat is run up with warm water say, 100 degrees in warm weather and 110 in cold weather, and the infusion of puerine, including the undissolved portion, is added to the bating vat, and the skins entered into the bating liquor. As the action of the puerine on the skins is exactly the same as a dung bate, the judgment of the operator must determine when the skins are “low enough.” It is not necessary to make a fresh bating liquor for each pack of skins, because the bating liquor improves with age. With each succeeding pack of skins, enough warm water is added to the bating vat to make up for the loss of liquor which is occasioned by the removal of the previous pack, and from 3 to 5 lb. of puerine for each 100 galls. added directly to the bating liquor; it is then in condition immediately to use again. The bate was found to consist of Sugar. Gelatin. Sodium } Ammonium } Chlorides and sulphates. Bisulphite of lime. Meal. As it is allowed to ferment without the addition of bacteria, it will be seen that it acts in quite a different manner to erodin, being more of a modified drench than a true bate, and is not in any way a perfect substitute for the dung bate.